1. Field of the Invention
The present invention relates to a metal complex colorant comprising an azo moiety, and more particularly, to a metal complex colorant which may embody various colors and have effective fastness, such as light resistance, water resistance and the like.
2. Description of the Related Art
In general, colorant are substances which exhibit inherent colors by selectively absorbing and reflecting visible light. Colorants are used in various fields embodying colors, such as fibers, foods, drugs, cosmetics, coatings, ink for inkjet printers or printing, pigmenting plastics or rubbers, manufacturing furniture, textile printing, and making papers or ceramics.
Colorant are classified into dyes and pigments. Dyes are colorful substances that may be dissolved in water or oil and dispersed as single molecules, and may bind to molecules such as fibers for dyeing. Pigments are substances that do not dissolve in water or oil and form an opaque colorful film in the form of a powder on a surface of a material.
In general, dyes may have a wide range of colors that are bright and vivid. However, dyes are not light/water resistant, i.e., they may be bleached/discolored by light or may be diluted by water or organic solvents. On the other hand, pigments have more effective light/water resistance than dyes. However, pigments have a narrower range of colors than dyes. Thus, much research has been conducted to enhance light and water resistance, and the like, of dyes, without reducing the variety of colors of dyes. One such dye includes a metal complex.
U.S. Pat. No. 5,095,100 discloses a method of producing a metal complex dye having an improved light resistance by forming coordinate bonds between metal and an azo group and a specific functional group in the dye molecule. However, the method requires the presence of the azo group and the specific functional group in the dye molecule, thus limiting the types of the colorants to which the method may be applied.